He won't carry passengers but he might serenade passing cargo ships, says a 71-year-old Venetian gondolier who set off from Vienna for Budapest in a bid to link the two cities by gondola for the first time.
Vittorio Orio, who already crossed the English Channel in 2001 and also paddled down the Hudson River in his typical Venetian vessel, will cover about 60-70 kilometres per day, with a first stop planned in Slovakia's capital Bratislava.
In total, the 300-kilometre trip - funded by private sponsors - will take about five days, with Orio due to arrive in the Hungarian capital on Tuesday.
A support team will accompany the gondolier down the Danube in a motorboat, and videos of the trip - which is tied to an Italian charity foundation helping children with cancer - will be posted on the video-sharing website YouTube.
Orio's past projects have included paddling from the Swiss city of Basel to Amsterdam in the Netherlands, across the Channel, and from Venice to the Vatican to visit the pope.
The gondolier chose the Danube for his latest project, as it is a "symbol of union between different nations and people," according to his sponsors.
The Danube is the second longest river in Europe and a major navigation route, running from Germany to the Black Sea via Austria, Hungary, Serbia and Romania, among others.